The present invention is directed to the field of X-ray detection systems.
There exists a need for improved systems and methods of screening baggage for explosives, weapons, and other contraband. Some existing systems employ X-ray scanners, computed tomography (CT) scanners, or other imaging devices to detect concealed objects. In some such systems, a CT scanner is preceded by an X-ray scanner, which performs a xe2x80x9cprescanningxe2x80x9d function to determine initial information on the contents of an article of baggage. Existing X-ray based systems provide differing degrees of sophistication in terms of their ability to analyze baggage based on the X-ray data obtained. Some, for example, balance the speed of the baggage screening with the accuracy and reliability with which contraband is detected. While the prescanning function discussed above may increase the accuracy and reliability with which contraband is detected, there exists a need for improved systems and methods of screening baggage.
One embodiment of the invention is directed to a method or apparatus for analyzing an object in which a dual energy X-ray prescanner performs a prescan of the object to determine prescan information about the object. Then, a CT scanner performs a CT scan on at least one plane of the object based on the prescan information. If the CT scan of the object includes or is in the vicinity of metal, then metal artifact correction of a reconstructed image from the CT scan may be performed using the prescan and CT scan information.
Another embodiment of the invention is directed to a method or apparatus for analyzing an object in which a prescanner, which need not be a dual energy prescanner, performs a prescan of the object to determine prescan information. Then, a CT scanner performs a CT scan of the object to determine CT information. A processor analyzes the CT information and the prescan information to determine whether to update the prescan information based on the CT information.
While the description and claims herein recite use of a CT scanner, such term is intended to cover any device that measures at least density of an object scanned by the device.